The "no" triggers:
-"unputdownable"
-when the listed title includes a description (So-and-So and the Such-and-Such: The Amazing Unputdownable Interesting New Story That Will Have You Reading Through the Night)
-saga
-generations
-descriptions beginning with reviews
The "yes" triggers:
-a very short description that doesn't reveal the whole plot
-"for fans of..." Looks like I'm the only sucker for this on this thread. Sure, half of them don't live up to the hype, but I still have to give it a go, just in case